Garvin Industries Door Jamb Switch Kit mounts in a door jamb to activate lights or other electrical items when the door is open. It consists of a push-button switch with a metal box and a cover plate. Mounting hardware is included. It is an all-purpose switch for indoor use on sliding or hinged doors in locations like closets, darkrooms and walk-in refrigerators. It contains a normally-closed contact so that the circuit will be ON when the door is open.